Maple was used to plot a
sphere, using cartesian coordinates. Below are the commands
which were used.
> top:=sqrt(1-x^2-y^2);
> bot:=-sqrt(1-x^2-y^2);
> plot3d({top,bot},x=-1..1,y=-1..1);
The resulting plot appears to the right. As can be seen, Maple has trouble where the plot becomes vertical. It would be better to use spherical coordinates. These will be discussed later in the semester.
Next, we talked about vectors, which is the subject of section 11.2 of the textbook.
The concepts of vectors and vector addition were illustrated using Geometer's Sketchpad sketches. I've converted these into Java Applets so you can play with them in your Web Browser. Note, your Web Browser must be Java capable, and have Java enabled. Note also that the applets may take a couple of minutes to load.
Various properties of vectors were discussed. The usefulness of vectors was illustrated by using vector methods to solve a geometry problem without having to use trigonometry.